<正>采用人工模拟水分胁迫方法，对华山松（Pinus armandii Franch）树种接种的菌根化苗和未接种苗的耐旱特性进行了对比研究，结果表明：随着水分胁迫的加剧，两种苗木的根系质膜相对透性和丙二醛含量上升，但二者相比，接种菌根化苗上升幅度较小；而叶绿素总含量、硝酸还原酶活性、根系活力及含水率下降，前者下降幅度比后者要低。综合分析表明接种菌根化苗抗旱性比未接种苗强。

The very good method to analyze the structural change of reaction process of polyvinyl alcohol modified UF resin by the traditional process alkali-acid-alkali is 13 C--NMR, and which extrapolate a possibly reaction. The structure analysis indicated that, under alkalinity condition, addition reaction was primary, reaction production was mainly monomethylolurea, the urea participated in the reaction completely, the formaldehyde was still in existence by polymerization, at the same time polycondensation reaction also happened. At a acid reaction stage, the polycondensation reaction was primary, the macro-molecule system was formed with the methylene or the ether linkage, the polymerization formaldehyde decomposed completely, and as the form of methylene glycol participated in condensation reaction. The third urea ioined might obviously reduce the free formaldehyde content of the reacting system, the reaction production was mainly monomethylolurea. The polyvinyl alcohol monomer chemical constitution had the good attribute on 13C--NMR, but the chemical shift that proved the polyvinyl formal didn’t examine, therefore in this experiment, the polyvinyl formal hasn’t been product.